/Engine/Source/Runtime/Engine/Classes/PhysicsEngine/ConvexElem.h
Finds the shortest distance between the element and a world position. Input and output are given in world space
The distance between WorldPosition and the shape. 0 indicates WorldPosition is inside one of the shapes.
float GetShortestDistanceToPoint ( const FVector & WorldPosition, const FTransform & BodyToWorldTM ) const